There’s one Irish historic church that does a free St Patrick’s Day breakfast after the Mass. It is awesome and the food is great and it’s so packed you can’t get a seat and they only do it once a year. Other than that I’m not aware of any “free parish meals” unless they’re meant for the homeless, or they’re some Lenten fast soup and bread and prayer thing.
I do hit all the great fish fries during Lent, and some of them are just amazingly good, but they are fundraisers and you pay (and worth every penny). They also tend to be jammed with both eat-in and take-out business. The better the food, the bigger the crowd.